The present invention relates to an emergency brake lock assembly for use with vehicles. More specifically, the present invention relates to an emergency brake lock assembly for use in vehicles that have an auxiliary door and lift assembly. The emergency brake lock assembly prevents the vehicle from moving while the lift assembly is being operated.
Buses that are used to transport handicapped passengers confined to wheelchairs typically include an auxiliary door formed in either the side of the bus or at the rear of the bus. When the auxiliary door is open, a lift assembly having a vertically movable platform is used to load and unload the wheelchair passengers from the bus through the auxiliary door. During loading and unloading, it is critical that the bus remain stationary to prevent injury to the wheelchair passengers and pedestrians.
In order to prevent the bus from moving while a wheelchair passenger is being loaded and/or unloaded, brake interlock systems have been developed that tap into the hydraulic brake lines of the bus to lock the bus brakes while the lift assembly is being operated. While this type of system functions well to prevent inadvertent movement of the bus while the lift assembly is being operated, the system suffers from several significant drawbacks.
For example, if the brake interlock device identified above is retrofit into a previously manufactured bus, a mechanic must tap into the hydraulic brake fluid lines in the bus in order to install the brake interlock device. According to the brake warranty offered by many bus manufacturers, if the hydraulic brake fluid system is modified, the manufacturer's warranty for the braking system is rendered void. Thus, when retrofitting existing buses including wheelchair transports, the owner of the bus is hesitant to install a brake interlock device that tampers with the existing hydraulic braking system.
Additionally, installing a brake interlock device that taps into the hydraulic braking system of the bus is difficult and time consuming. Typically, to install the interlock the mechanic must have access to the underside of the bus, which may require the mechanic to work on his back beneath the bus. When installing the brake interlock device, the mechanic must be sure not to introduce any leaks into the braking system that would drain the hydraulic fluid from the braking system, thus rendering the vehicle brake system ineffective.
Therefore, it is an object of the present invention to provide an emergency brake lock assembly that can be easily retrofit to existing vehicles without tampering with the existing hydraulic braking system. It is an additional object of the invention to provide an emergency brake lock assembly that prevents the vehicle from moving while the auxiliary door is open and the lift assembly is being operated. It is a further object of the invention to provide an emergency brake lock assembly that energizes the lift assembly only when the emergency brake is engaged and the emergency brake actuator is securely held in the engaged position. It is an additional object of the invention to provide an emergency brake lock assembly that includes a locking member that engages the emergency brake actuator contained in the bus and locks the emergency brake actuator in the engaged position. It is an additional object of the invention to sense the opening of the auxiliary door and engagement of the emergency brake to both retain the emergency brake actuator in the engaged position and energize the lift assembly.